Lack of temperature stability on a Bricoletta - will PID help? - Page 2

[edwa]

Greetings. I thought I'd post an update to my attempts to achieve some temperature consistency. I have come to see the value in having a data logging capacity because often times I don't catch all of the info. I also see that in order to be of any help to others you really need to chart these results. The best solution so far has been to video tape some of my pulls.

Eric has been extremely helpful in finding a working method. Here's what has been working fairly consistently "for me" with my Volante's set-up. First shot of the morning has a long idle (warm up) of approx 1.5 hours. I flush about 10 oz with the PF in the group until the Fuji readout hits 189. Then I remove and dry the PF and build. It takes about 2 minutes from the end of the flush until the Fuji readout show the temp working its way back up to just shy of 194 F when I then pull the shot. My Fuji readout then starts in the 205 and settles in to 203.+ range. If the readout drops below 201 I can taste the souring. I will admit that I find it harder to judge the taste of increasing levels of overheated shots ... to a point and then its a sinker.

The shorter idle shots are not as consistent, depending on idle length and readout. Generally a short idle requires a 4 oz flush and then I watch my readout until its just clicked to 206.9 or close.

In the end I am pleased that I added the E61 adapter. It has fine tuned my routine and gives me valuable feedback when I'm trying to vary the shot's temp.

If someone needs video I can shoot it for you, otherwise I'll just let this thread fade away until and if Terry posts his Bric mods.

Once again, I apologize for the lack of my scientific methods and equipment. I didn't want to just help myself and then walk away.

By the way, and this is unsolicited, I had been meaning to try the Big Truck Espresso and this thread motivated me to finally order some. Delicious, in a word. Reminded me of Black Cat but not as overpowering with the bittersweet chocolate AND didn't upset my stomach like B.C. Great with milk in a 6 oz capp, my wife loves it as an Americano. As a straight espresso as robust as my tastes want to go.

[Kristi]

I had a Bric at one point.



I did insulate the boiler (and got Jim pissed at me in the process, for daring to suggest that any machine might be better if modified)(which was the only reason why I sold it), and insulated the nose (ugly but effective) but the change was more to faster warmup. With both those I do think it was more stable. (nose insulation will MARKEDLY alter where your pstat needs to be.)



Temperature readings: In the above thread, I saw some mention of Eric's nose probe but essentially I could not ascertain who was reading their temperature how - where was the tc? - this is all important, not just that you are somehow reading the temp...



I did have Eric's probe on my Bric for a bit, and did not find it useful.

I did PID my Bric (tc on back side near bottom) for a bit but found it killed the Bric's fair steaming ability.

I used various different methods for measuring temp
1) tc under shower screen
2) tc attached at various points on the side of the nose
3) tc attached inside hex socket of nose bolt
4) Eric's nose probe
and probably a few others I have long forgotten.

All were lots of fun but ultimately none were very useful.


Adjustment on the Bric is mainly via Mater pressurestat which has a wider deadband that I like. THIS IS A PROBLEM. But I found that I could tune the pressurestat to give me a fine brew and also give me dependable steaming. But at that point, I don't think it is much different than any other E61 HX. And I DO love E61 HXs!

Terry mentioned horizontal boiler with vertical HX as being a factor. Dunno. (hey Terry, answer my email re the ceme pressurestat - that's important!) I have had both horizontal and vertical E61 HXs. The Cimbali with horizontal boiler and horizontal HX spoiled me rotten and I appreciate that in the Tea. But, YES, DEFINITELY, pull the little water level sensor in the Bric UP - it has a tendency to be too low, and this will markedly affect temp stability during the pull.


But not having the faintest idea how the temp was measured in each case makes it very hard to get anything from the posts and harder to make a suggestion other than "play with your pstat, and your water dance, until you find what tastes right FOR YOU for the particular beans/roast you are using".

The great thing about all this is that while you're playing you get all these fantastic espressos - pure torture!

[Grant]

I have an automatic volumetric controls Bric with rotary pump. I have done a lot of testing/playing to achieve/test a temperature stability routine, and have found (using a Scace thermofilter) a very rock solid temperature consistency as below...I will try post a video as soon as my camera is back from repairs (it takes decent mpg's but got sand in the lens from a Mexico trip).

But, what I have come to find after experimenting is with the way mine is set up (I think we are at about 2400ft above sea level or so) - insulated boiler, pressurestat bouncing from about 1.05 to about 1.15 bar, is that from a long idle I flush 5oz (which is only about 2 seconds after the hissing/sputtering ends), and then pull the shot about 20seconds later. I get 199 degree shots that only vary about ± .5 degrees during the entire shot.

No problems with cooling during the shot at all. If anything...I see temps rise, not fall.

Grant

[Kristi]

I was out looking for info on what Dan calls rebound (the pause between the flush to get rid of the steam, and the extraction), and I wound up back here. Terry suggested upping the Bric pstat to give it more stability and I do recall having to do that. Worked better all the way around and made it an enjoyable machine - pstat 1.3 as I recall.

I was playing around late this evening with sticking a tc in and then locking the pf in and found that the squishy gasket that I'm using seals nicely around the tc wire - too nicely as at first I was trying to use that little gap to let water out while I was measuring temp. So I finally just ground some coffee and measured it that way. Rock solid through the pull, though too high so I turned the pstat down a skitch. Course I pointedly only did a 7 sec flush so I should have expected that - needs more like 10... (45sec pause)

Yet again, I put myself in beginners shoes: read Dan's article (for the 14th time)(each time I understand it better) and extracted what it meant to me (in my words, so any mistake is MINE!):
---
From Dan: particularly for HX: flush - pause - extract

Flush amount affects temp at mid to end of pull

rebound / pause after flush before pull : "15-35 sec, certainly less than 1 minute."
short = no temp hump to small temp hump at beginning of pull
long = medium to big temp hump at beginning of pull
---


something about HX love...

[edwa]

Grant,

This morning I tried your method with the exception that I used a 2 count after the end of the hissing/sputtering instead of watching the volume of water that was flushed. I could see the shot temperature stability you wrote about. My machine fluctuates between 0.9 and 1.10 versus yours of 1.05 to 1.15. Also, I'm just a few feet above sea level.

The big difference in my results were that my thermocouple which is positioned at the water path intersection as prescribed by Eric's instructions read 209.8, humped to 210.3 and finished down around 209.4. No complaints about the stability just how hot this sucker persists on getting. Out of curiosity what are you doing for your short idle shot?

I'm contemplating Kristi and Terry's advice of upping the pstat.

Terry, anything new to add since your posting a couple of weeks ago?

[kanoyu]

edwa,

I don't know if this is any help, but I've been struggling to fine tune temperature on my Salvatore for almost a year now. I can hardly believe that others are flushing so little (on other HXs) after the sputtering stops. I need to do a 6-7 second count to get the temp down to about 206, as measured by Eric's thermocouple (it takes at least 10 seconds just to get to 212 degrees and the sputtering subsides). This means that from a HOT idle, I end up flushing about 8-10 oz of water. I then wait 30 seconds for a 203.7-204.4-203.5 hump (I have determined about a 1 degree difference between thermocouple temp and 'puck' temp by using a Scace device simultaneously). If I go about 25-35 seconds between shots, I can keep a pretty stable 202-204 on the thermocouple. But even a 3-minute lapse will require another 6-oz flush. I have adjusted the pstat down from 1.05-1.25 to 0.95-1.15 already and don't want to go much below that, so I'm living with flushing a lot (which is getting to be a bit of a pain with the pour over).

I know it's a completely different machine, and I am by no means an expert, so it maybe comparing apples to oranges, but try flushing more, maybe until you get to 206 on the tc, pause and then go.

Good luck.

[Kristi]

remember that the temp at Eric's tc is 5-10deg F above the temp in the brew chamber.

[kanoyu]

Please excuse my ignorance. By 'brew chamber' do you mean where the coffee puck is being brewed (filter)? If so, this is not corroborated by my simultaneous tc device/Scace readings on an Omega meter.... I've had up to 2.5 deg F differences, but nothing approaching 5-10 deg F. Of course I could be measuring or monitoring incorrectly....

[Kristi]

'brew chamber'

yeah, directly above the tamped coffee grounds, below (not touching) the screen.

[HB]

I've had up to 2.5 deg F differences, but nothing approaching 5-10 deg F. Of course I could be measuring or monitoring incorrectly....

The difference depends on when you measure since the two readings merge later in the shot:


Temperature within the valve chamber exit (blue) versus thermofilter (red)

[edwa]

kanoyu, greetings and thanks for sharing your trials. I have been flushing about the same amount as you and our pstat settings are very close, though I need to wait considerably longer before I pull.

I'm jealous of the ability to have a Scace device on hand as I have no way to measure the temp exiting the group head. There was once talk of a Scace kit that could be rented but that probably proved to be too troublesome to pull off.

I've had up to 2.5 deg F differences, but nothing approaching 5-10 deg F. Of course I could be measuring or monitoring incorrectly....

You underscore the variances of different machines. I have, based on communications with Eric, assumed about a 4 F degree difference give or take. Eric's installation manual in the first paragraph says,

The difference between the temperature that you will be measuring using this adaptor and measured temperature of the water hitting the puck is approximately 7-9 degrees F and may vary with different machines and different brew conditions.

Although I've seen Dan's graph before I can't be sure that my machine is doing the same as my eyes flick back and forth from readout to watching the extraction and without data logging I can't be a reliable source.

I feel your pain with the hassle of the pour-over. Although I'm plumbed I'm burning through Everpure cartridges, my next step is to take the Everpure off the line and just let the water softener be the only intermediate step. Although my drain is also plumbed I've started collecting the flash water and using it to rinse out the PF after the shot.

[kanoyu]

edwa,

One of the challenges for me has been the (lack of) consistency, or repeatability, of what I observe my machine is doing. This morning, for example, I followed the protocol that I outlined to you, got no hump (from the tc device), and went from 205.7 deg F to 203.8 deg F at a fairly regular pace (didn't record, so I don't know how linear). Good pour, nice crema, rich taste at first, followed by an unpleasant finish--may have soured on me (or it could just be OLD coffee!). In terms of variance between tc device and Scace, even that varies, as Den mentioned, during the the shot (intra-shot), but also (for me) from shot to shot (inter-shot). For example, I will get greater intra-shot variance on the first pull, and less intra-shot variance on the next one (30 seconds later). I suppose it could be that the Scace device is already super-heated from the first pull. I also get greater stability with successive shots (as registered by the tc device).

Taking a chapter out of other postings concerning method, try to work on one thing at a time. If stability is what you're after, focus on that. Might I humbly suggest the following:

- give your machine plenty of time to warm up
- prepare 2-3 baskets with the same coffee, weight, grind, dose, and tamp
- flush to target temp (on tc device), say 205 (if 4 deg F is your variance, 201 maybe good to shoot at)
- lock first basket and wait 35 (or 40, 45, 50-but try to be consistent) seconds
- pull shot and observe temperature fluctuation
- use the next 35 (or 40, etc.) seconds to remove portafilter, remove basket (helps if you have ridgeless or no spring clip), and lock second basket
- pull second shot and observe temperature fluctuation
- use the next 35 (or 40, etc.) seconds to remove portafilter, remove basket, and lock third basket
- pull third shot and observe temperature fluctuation

Don't worry too much about watching the pour, focus on temperature stability (if that's what you're after). Once you have your routine down, you can check the pour out. Also, there will be a lot going on, so you might want to video the thermometer so you can check it later (unless you have data logging and plotting capability).

It might be easier, and you'd burn through a lot less coffee and water, if you had a Scace, but I'm not sure it would give you any more information on stability. Once you have addressed the stability issue (and I hope you will meet with success here), then you can adjust flush amounts to zero in on temperature (tc device reading relative to taste).

Finally, if I had been nearly as methodical as I am suggesting, I probably wouldn't have struggled as much as I did (am?). I'm sure you will be wiser than I have obviously been.

BTW, that's exactly what I do with my flush water!

Good luck.

[Kristi]

I'm jealous of the ability to have a Scace device on hand as I have no way to measure the temp exiting the group head. There was once talk of a Scace kit that could be rented but that probably proved to be too troublesome to pull off.

Why be jealous - this measures it EXACTLY, and in actual brew situation, and costs almost nothing.

the hook shaped "wire" to the right isn't a wire but a reflection of the wire



Side view of tc wire - fine gauge K-type - doesn't last forever but when you want just nip it off and make a new tc by baring the wires and tightly twisting together. is calibrated quite accurate.

[edwa]

Hey Kristi,

I've got a Type K and a cheap reading Celsius multimeter but its read rate is too slow. I have it snaked up the single spout PF an through a sponge for "some" flow restriction. The cost factor would be getting an Omega or Fluke. Your over the lip method would probably work better.

kanoyu, I have similar consistency problems from day to day. I'm pretty happy with the way things pull and taste and my procedure gets me close. I've come to the attitude that, in terms of temp, "close enough" works as long as I'm not hitting the "shoulders" and coming up bitter or sour. Kind of like tuning a guitar string by ear rather than a meter.

[Kristi]

The cost factor would be getting an Omega or Fluke.

Needing that much accuracy is a fallacy that some seem to hold to. It's nice, but far from necessary.

[kikuchio]

edwa,

I don't know if this is any help, but I've been struggling to fine tune temperature on my Salvatore for almost a year now. I can hardly believe that others are flushing so little (on other HXs) after the sputtering stops. I need to do a 6-7 second count to get the temp down to about 206, as measured by Eric's thermocouple (it takes at least 10 seconds just to get to 212 degrees and the sputtering subsides). This means that from a HOT idle, I end up flushing about 8-10 oz of water. I then wait 30 seconds for a 203.7-204.4-203.5 hump (I have determined about a 1 degree difference between thermocouple temp and 'puck' temp by using a Scace device simultaneously). If I go about 25-35 seconds between shots, I can keep a pretty stable 202-204 on the thermocouple. But even a 3-minute lapse will require another 6-oz flush...

this seems to use and waste a large amount of water. reading many of the threads about hx machines the flushing routines all seem to do so. is there any alternative while still producing an admirable cup?

kikuchio

[Kristi]

this seems to use and waste a large amount of water. reading many of the threads about hx machines the flushing routines all seem to do so. is there any alternative while still producing an admirable cup?

kikuchio

Lower your pstat and work toward short flush and short pause - say 10 sec each.

[erics]

Attached are some temperature graphs of cooling flushes and subsequent group cooling/heating ONLY as measured on a Quickmill Anita using the thermocouple adaptor and a type T thermocouple. These graphs DO NOT represent any pulled shot. The combination of the thermocouple and the meter (Omega HH506RA) just happen to be pretty accurate as best I can determine - ice bath and boiling water and the thermocouple is positioned fairly accurately at the "intersection" as detailed in the thermocouple adaptor manual.

Each and every morning (Anita is clean and has been on for at least 90 minutes due to timer) I flush to about 185 F and start grinding, weighing, leveling, tamping, etc., etc. I flush into my one favorite cappy cup and, by all accounts, its turns out that I am flushing about 8-9 ounces (the cup does overflow). I am pretty anal about how much coffee goes into the LM ridgeless (17.0 g's) and equally anal regarding the leveling operation. I have timed myself and it takes me about 1-1/2 minutes to fully prepare the basket. This could be hellacious in a cafe.



As the grouphead is heating back up due to the action of the thermosyphon, I drop the basket into the PF (at, say, 197.5) that has been waiting patiently in the group and lift the lever at 198.0. This results in a good shot.

This particular method certainly uses up some water especially if you're making a single drink every 20 minutes or so in the AM but it does result in some pretty stable (and, more importantly, repeatable) temperatures. I have promised myself that I was going to try the shot initiation at GH temps of 197, 199, etc. etc. but the drinks at 198 are too good and I am, of late, lazy.

As always, this MS Excel file is available for the asking.

Skol,

Eric S.
erics@erols.com

[erics]

And here is a temperature graph of a simulated shot pulled through a Scace Thermofilter starting with the grouphead temperature at 198 F.



Again, the MS Excel file is available for the asking.

Skol,

Eric S.
erics@erols.com

[beta14ok]

Hey Eric,

I did get your email with these data last Tuesday, but I've been out alot, and haven't had the chance to either respond or run a rigorous simulation on Mondiale. But these profiles look similar in "pattern/profile" to what I see with Mondiale. I don't have a recording device and I'm not gonna have time to "play" until maybe Sunday afternoon.....but in principle, this should be a better approach than surfing the temperature drop during the flush.

The downside as you suggest,. will be the increase in time to complete and increase in water-volume.....which in my case is not too much of an issue really on either count....as I'm usually the only one making an espresso, and I'm direct plumbed.

I'll give your scheme a whorl and make another entry to this thread with-in-the-week-or-so.

Cheers,
dmm